I had this talk with a member of my family. Water is a chemical, salt is a chemical. Just because you don't immediately know what it is, doesn't mean its bad.
I’m sure they know, but maybe this is word drift or shorthand for “harmful chemicals”. That’s a lot more plausible than literally turning “literally” into its opposite
It's more of a lack of understanding of chemistry, this chemical compound contains something harmful in another form, but it is completely harmless in the form that it takes in this food or vaccine, etc.